Thousands of pairs of shoes were placed on the lawn of the U.S. Capitol on Tuesday, roughly one for each child who has been killed in school shootings since the 2012 Sandy Hook massacre, according to activist group Avaaz.

The group said in a statement that they collected 7,000 pairs of shoes for the memorial to bring “the heartbreak of gun violence to Congress’ doorstep.”

That number is all children killed with guns, not just those involved in school shootings. The number from school shootings is around 140-150. The deaths included in that 7,000 are those that occurred at home, on the streets, and basically anywhere else.